1. Field of the Invention
The present invention relates to a three-dimensional design section structure of a meter for automobile.
2. Description of the Related Art
There are meters for automobile which are devised to enhance the visibility of the dial (for example, see Japanese Patent Application Laid-open No. 2010-78442).
As a technology of this type, a three-dimensional scale structure (a three-dimensional design section structure) of a meter for automobile is known in which, as illustrated in FIGS. 5 and 6, three-dimensional scales 505a and 505b (three-dimensional design section) that are protruding in nature are disposed on a prism (a light guiding body) 503. The prism 503 is placed on the undersurface of a dial 501 for the purpose of illuminating the dial 501. The three-dimensional scales 505a and 505b protrude via through holes formed on the dial 501. According to this constitution, the three-dimensional scale structure enhances the visibility by the light guided to the three-dimensional scales 505a and 505b. 
The prism 503 is housed in a meter case 509. The outside of the three-dimensional scales 505a and 505b in the radial direction are covered by a decorated ring 511. On the rear surface of the dial 501, light sources (not illustrated) of white light are disposed for the purpose of illuminating the entire dial as well as illuminating the three-dimensional scales 505a and 505b. That is, a primary color illumination light 513 used for illuminating the entire dial 501 represents the same white light as the primary color illumination light 513 used for illuminating the three-dimensional scales 505a and 505b. 
In this type of three-dimensional scale structure, regarding the red zone of the tachometer, the light exiting from the three-dimensional scales 505a is supposed to be a colored light 515 that is colored with red color. For that, in a red-color-light requiring portion on the rear surface of the prism 533 (i.e., in a portion on the rear surfaces of the three-dimensional scales 505a), solid coating of red color printing 517 is applied as illustrated in FIG. 6. Moreover, on the front surface of the dial 501, auxiliary scales 519a and 519b are separately printed in red color in between through holes 507 with the aim of enabling visibility of the red color during daylight too. Meanwhile, the colored light 515 that is guided by the prism 503 and that is reflected from the red color printing 517 is made to reflect at a different angle than the normal line of the reflecting surface using a diffusing surface.
However, in the conventional three-dimensional scale structure described above, the primary color illumination light 513, which is the direct light having white color and which is used for illuminating the entire dial 501, exits without being reflected from the red color printing 517 applied on the rear surface of the prism 503. As a result, the primary color illumination light 513 becomes visible from the three-dimensional scales 505a that are intended to be red in color in the red zone. Moreover, when the auxiliary scales 519a and 519b are printed in red color in between the through holes 507 of the dial 501 with the aim of enabling visibility of the red color on the dial 501 during daylight too, the transmitted light of the auxiliary scales 519a present in the area corresponding to the red color printing 517 has different color shades than the transmitted light of the auxiliary scales 519b present in the area not corresponding to the red color printing 517.